Sensitization of photographic emulsions



Patented June 14, 1960 ice 2,940,851 SENSITIZATION OF PHOTOGRAPHICEMULSIONS Dorothy J. Beavers, Charles V. Wilson, and James L. Graham,Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., acorporation of New Jersey No Drawing. Filed Nov. 27, 1957, Ser. No.699,197

16 Claims. (Cl. 96-66) This invention relates to the sensitization ofphotographic silver halide emulsions with certain quaternary ammoniumsalts, e. g., pyridinium and quinolinium salts.

The sensitization of photographic emulsions with compounds containingquaternary nitrogen atoms has been known for many years as shown by theCarroll US. Patent 2,271,623, granted February 3, 1942. A representativequaternary salt sensitizing agent of that patent is the compoundethylene-bis-oxymethylpyridinium perchlorate.

We have discovered certain compounds containing quaternary nitrogenradicals which exhibit improved properties as sensitizing agents forsilver halide emulsions, Emulsions containing the compounds of theinvention are appreciably more stable than emulsions containing thementioned quaternary compounds. Accordingly, upon the aging of emulsionscontaining the new sensitizing agents, less fog is developed and theemulsion speed is maintained. Also, photographic emulsions containingthe new quaternary nitrogen compounds maintain their speed over a widerrange of development conditions than do emulsions sensitized withpreviously known alkylenebis-pyridinium salts such asdecamethylene-l,10-bispyridinium perchlorate. Thus emulsions containingthe latter compound as a sensitizing agent can be expected to lose anappreciable amount of speed when developed with a developing solution ofhigh sulfite content of the order of 100 grams of anhydrous sodiumsulfite per liter, whereas the emulsion speed is maintained in suchdevelopers when the emulsion is sensitized with the quaternary salts ofthe present invention.

When the emulsions are sensitized with the quaternary salts of theinvention and are used in processes of color photography, that is, inmultilayer color films adaptable to the reversal process of colorphotography, the first development step with the usualMetol-hydroquinone developer produces less fog than when the emulsionsare sensitized with other quaternary salts such as that of the aboveCarroll invention.

It is interesting to note that Howe and Glasset British Patent 566,314and Vanselow and James PSA Section B, 36-40 (1953), have shown thatcertain quaternary nitrogen salts such as n-dodecylpyridinium bromide,n-dodecyltriethyl ammonium bromide, etc, are not efiective in increasingspeed When development is carried out with a pphenylenediamine as thedeveloping agent such as used in color photography. In fact, it wasshown by these workers that development with the p-phenylenediaminedeveloping agent in the presence of the quaternary nitrogen saltsretarded the development rate. The quaternary salts of the presentinvention when employed in the emulsions as sensitizing agentsunexpectedly do not retard development when development is carried outwith a pphenylenediamine type developing agent.

The quaternary salt sensitizing agents of the invention arebis-quaternary salts having the following general formulas:

I QRCONH(A),, NHCOR'Q' and II QRCONHAQ' where Q and Q represent the sameor different organic radicals containing quaternary nitrogen atoms suchas trialkyl ammonium salt radicals and cyclammoniumsalt radicals, e.g.,pyridinium salt radicals or quinolinium salt radicals, R and R representthe same or different radicals, which may be alkylene, such as (CH andincluding a carbon chain separated by other atoms such as O or S, 2)n2)n' or 2)n 2)nb n and n' being integers of from about 1 to 10. Thetotal chain length of R and R must be such that the number of atoms inthe linear chain joining Q to Q does not exceed about 30. (The termatoms as used herein refers solely to the actual elements that composethe chain and not to any groups that these elements may carry. Forexample, --(CH is considered to be a IO-atom chain, the hydrogen atomsbeing disregarded;

is a 12-atom chain, the oxygen and hydrogen atoms being disregarded.) Acompound of the above structure wherein the chain contains 34 atoms hasbeen found not to be useful as a sensitizing agent. Likewise compoundshaving less than about 14 atoms in the chain are not very usefulsensitizing agents, the sensitizing activity of the compounds decreasingrapidly in compounds having less than about 14 or more than about 30atoms in the linear chain connecting Q to Q. In a preferred embodimentof the invention, therefore, the compounds contain from about 14 toabout 30 atoms in the chain.

In Formulas I and II above, group A represents a linear chain of one ormore atoms of carbon which may or may not contain sulfur, oxygen ornitrogen as an intermediate linkage. Since n represents the positiveintegers 1 or 2,

when )1 equals 1, the group A is not present and a group of compoundscontemplated by the invention have the formula HI QRCONHNHCOR'Q' IVQRCONHANHCOR'Q In the above formulas the number of atoms comprising A islimited by the number of atoms in R and R. since as mentioned above, thetotal number of atoms in'the chain connecting Q to Q must not exceedabout 30. Thus in Formula IV, A may contain as many as about 24 atoms ina linear chain when R and R are methylene groups. However, in suchcompounds where A represents an alkylene group, group A can contain only2 to about 24 carbon atoms in a linear-chain since it has not beenpossible to synthesize compounds in which A equals a CH:-- group.

oxygen or sulfur wherein =ri and n are positive integers of the order of1 to 10 selected "so that the linear chain of atoms be:

tween Q and Q contains from about 14 to about 30 'atoms. In the exampleshereinafter are provided compounds in which A has been varied as aboveto obtain very eifective sensitizing agents.

Representative bis-quaternary salts having the above formulas are asfollows:

I. 7 4,11-diaza-3,12-dioxotetradecane-Ll4 'bis(pyridinium perchlorate)enema-51 XI. 10,15-diaza 9,16edioxotetracosane 1,24 bis(pyridiniumperchlorate) XII. 12,15-diaza-11,16-dioxohexacosane-L26 bis(pyridiniumperchlorate) 5 X111. 12,19-diaza-11,20-dioxotriacontane-1,30bis(pyridinium perchlorate) XIV. 12,19-diaza-l1,20-dioxotriacontane-1,3Obis(isoquinolinium perchlorate) V XV.12,23-diaza-11,24-dioxotetratriacontane 1,34 bis (pyridiniumperchlorate) XVI. 7,13-diaza-6,14-dioxo-10-thianonadecane-1,19 bis(pyridinium perchlorate) I ,7 XVII. 7,10,17,20-tetraza 6;9,'18;2ltetraoxohexacosanei. l;26-bisf( .py'ridinium perchlorate) l5 XVIII.3-aza-4-oxotetradecane-1,l4 bis(pyridiniumperj chlorate.) ,o V r is V:p-PhenyIene-bisQ-a a-E oxotridecanejpyridinium perchlorate) 7 xx.7,18-diaza-6,19 dio;rotetracosane 1,24 bis(trimethyl ammonium p toluenesulfona'te) A better understandingoftheiinvention can be obtained byconsideration of the structural formulas of a number of the compounds ofthe invention contemplated by the general formiilas above.

COMPOUND v COMPOUND XVI qomnoonmomnswnnmnootomn if 26104 I o'n,.comron,c orrmomymnooonmnoo onm i 1 COMPOUND XVII vCOMPOUND XIX compoundCONH IQNHCO (CH -+NC H 2010 (XV) containing 34 atoms in the linear chainconnecting the quaternary nitrogen atoms is ,ph'otographically inert anddoes not impart any appreciable amount of sensitivity to silver halideemulmom. 7

i The sensitizing eifect of the representative bis-quaternary n'itrogencompound I of the invention having the structure compared with thefollowing bis-quaternary compound Jr .in which the amide linkage isreversed, .is interesting.

In compounds I and Ir the same number of atoms are present inthe chainseparating the quaternary nitrogen atoms yet unexpectedly compound I issuperior in regard to its sensitizing efiect upon silver halide as shownby the data in Example 7.

I The compounds of the invention having the above general Formulas I,I1, I11 and IV are prepared as indicated in the following flow diagram:

6 w-Bromocaproylchloride, 140 grams (0.66 mole) was dissolved in 500 m1.of dry ether and this solution added through the dropping funnel over aperiod of one hour, keeping the temperature below A thick slurry formedimmediately and was stirred overnight, then alr XRCOOH The above diagramshows that the unsymmetrical diamides can be prepared by reacting thediamine compound consecutively with different w-halo acids, then acidhalides. The symmetrical amides are prepared by reacting two moles ofthe w-halo acid or acid chloride with the desired diamine in a singlestep followed by the quaternization step. For photographic purposes, thequaternary nitrogen compounds obtained as the halide salts arepreferably converted to inert salts such as the perchlorate asillustrated in the syntheses hereafter. In the above flow diagram Xrepresents a halogen atom, e.g., chlorine, bromine or iodine or alkyl oraryl sulfonate ester; R, R, A and n, Q and Q have the significance givenabove. Representative bis-quaternary salts of this type are synthesizedas follows:

COMPOUND VI w-Bromocaproic acid w-Bromocapronitrile, 202 g. (1.15 mole),350 ml. of 48% hydrobromic acid and 350 ml. of glacial acetic acid wererefluxed vigorously for fifteen hours. The product was diluted with 500m1. of ice water and extracted three times with 500 ml. portions ofether. The solvent was removed on the steam bath and the residuestripped under reduced pressure to remove any acetic acid which may havebeen extracted along with the product. The 216 g. of crude oil wasfractionated under vacuum to yield 181 g. (81.5% yield) of a colorlessoil, B.P. 120-140/ 1.2 mm. which solidified to white platelets M.P.27-29".

To 250 ml. of dry benzene was added 280 g. (1.44 mole) of w-bromocaproicacid. The solution was stirred while 230 g. of oxalyl chloride was addedover a period of thirty minutes. A vigorous evolution of hydrogenchloride took place although no temperature rise was evident. Thesolution was allowed to stand one hour at room temperature, then heatedto 60 for two hours. The solvent was removed at 60 under the aspirator.The pale yellow oil weighing 323 g. was fractionated through a 6"Vigreau column. A pale yellow oil with an acid chloride odor weighing291 g. (95%) was collected at 95102/1 mm.

7,14-diaza-6,1S-dioxoeicosane-LZO-dibromide To a 5 liter flask equippedwith stirrer, dropping funnel and condenser was added three liters ofdry ether. Thirty-eight grams (0.33 mole) of freshly distilledhexamethylenediamine and 73 grams (0.73 mole) of triethylamine wereadded to the flaskg'ving a clear solution.

l CsHsN (or tert. amine) lowed to stand for twenty-four hours at roomtemperature. The thick white slurry was filtered as dry as possible withsuction and the remaining traces of ether removed in the vacuum oven atroom temperature. The finely divided white powder was vigorouslyslurried in 2 liters of ice water for fifteen minutes, then filtered.The filter cake was reslurried with ether, filtered, and dried at roomtemperature in the vacuum oven giving 152 grams (98% yield) ofcream-colored solid of M.P. 110.5112. If the melting point of the solidis much lower, the dibromide is dissolved in a minimum of methanol,filtered, ether added to the cloudpoint, and the solution chilled in aDry Ice acetone bath. With vigorous scratching a crystalline solid ofexcellent melting point is obtained. The analytical sample was obtainedas white needles from acetone and melted at l10-1l2.5.

Analysis.Calc. for C18H34BI'2N202: C, H, N, 6.0; Br, 34.0. Found: C,45.8; H, 7.0; N, 6.1; Br, 33.7.

7,14-diaza-6,1 5-dioxoeic0sane-1,20-bis(pyridinium perchlorate) Onehundred thirty g. of 7,l4-diaza-6,15-dioxoeicosane-1,20-dibromide wasadded to 700 ml. of pyridine and the mixture heated to reflux for 2hours. (The solution began precipitating the quaternary salt as an oilafter the first 20 minutes of refluxing.) The mixture was cooled, theexcess pyridine decanted and the dark orange oil slurried with etherseveral times, the ether being decanted each time. The syrupWas'dissolved in a small amount of methanol, and dry ether added untilno more oil precipitated. The ether was decanted and the trace ofsolvent removed on the steam bath under vacuum leaving 177 g. of a darkorange oil which contained no pyridine odor.

The oil was dissolved in 500 ml. of methanol in a flask equipped with anefiicient stirrer. A solution of 95.0 g. (0.68 mole) of sodiumperchlorate monohydrate in 500 ml. of acetone was added and the thickslurry heated for one-half hour on the steam bath. The sodium bromidewhich had precipitated was filtered off and the solution concentrated toabout 21-300 ml. volume. Acetone, 300 ml., was added and the mixtureheated. The sodium bromide which precipitated was filtered off. Thesolution was chilled in a Dry-Ice acetone bath and with vigorousscratching, dry ether was slowly added to the cloud point. Thescratching was continued until a solid precipitate appeared, or if anoil appeared, the excess ether was removed, the solution chilled and theagitatediorJS minutes.

talline 'solid drie'd the vaeuum"'ovena. 'l'lie"dflaromider weighed 285g. (92%) and had a .M.P. of"'101925-1062'52 Yields :of".'8598 %*ofproduct havebeen. obtained reaction;

melting as low as 50 have proven satisfactory as photographicsupersensitizers.

The analytical sample was obtained from methanolether as a whitesemi-crystalline solid, M.P. 60.5-63.5 Analysis.--Calc. for C I-I Cl N QC, 50.4; H, 616; N, 8.4; Cl, 10.7. Found: C, 50.3; H,'6;2; N,-8.:5;'Cl,'

COMPOUND X LZO-diaminodecane A twelve liter flask wasequipped with apowerful stirrer, an efficient condenser, and a powder funnel. Eightliters of dry ether were added to the flask and the apparatus swept outwith a stream of nitrogen. Granular lithium aluminum hydride, 100 g.(2.6 mole) was added through th'e powder funnel under -a nitrogenatniospherew The funnel was replaced by a dropping-funnel and a solutionof '342 g.- (2.6 mole) of anhydrous aluminum chloride in one liter ofdry ether was added as rapidly as possible and the resulting slurrystirred 'for 15= minutes.-

A -soldtion 015213 g. (1.3 mole) of sebaconitrile in 250 mll-ofrdryether wasnow added'through the dropping-funfielrapidly-- enough to causea noticeable reflux. About one-hour is necessary for the completeaddition of the nitrile The grey'mixture was refluxed for two hour's,-then stirred-"at room' temperature overnight.

The lithiumaluminum=hydride-diamine complex wasde'composedbyslowlyadding a solution of 250 g. of sodium hydr'oxide in =one-litcr-owater through the dropping funnel while allowing most'of the ether to:escape. Oneppound of sodium chloride was added to -the-resulting greyliquid slutry and the mixture stirred -vigorously with two 2"1.portionsof-hot benzene, thebenzene layers: being decanted each time. The benzenewas removed r' from .the -extracts gorrtheistearn bath under. vacuumleaving 129 g. of a colorlessoilwhich solidified to a white crystallinemass of decamethylenediamine of M.P. 55 5725 The diarnineshou1d-beprotected from the atmosphereasit readily picks-upcarbondioxide from' the air forming thedicarbonate salt. 7

The. remaining slurry was extracted continuously with" benzene 'inpaliquid liquid extractor for sixteen hours giving' .an"'additiona1 44.5gxof diamine possessing a slight yellow color with M.'P:"53'56'.Theoverall yield of' 1;10 diarniuddecanesuitablefor-further reaction is173.5 g. (78%"); V

7,18-diaza-6,19-dix0tetracosane-1 ,24-dibromide oneyhundred one grams(0.59 mole) ofl,10-diaminodecane was dissolved in 500 ml. of drybenzene. This solutio'rn-was: addedjto a l. flask equipped with aneflicient' stirring motor, a dropping funnel and condenser.Tricthylamine, 130g. (1.29 mole) was added to the solu-, tionzfollowedbythe addition of 3 liters of dry etherp A--:solutionaof;250 g. (1.17mole) of w-bromocaproyl- ChLOfld3:iini-200.m1.;Of dry ether was added tothe turbid solution-over :a period of one hour, keeping the tempera-.tureiofrtheaslurry below 25; The thick slurry was stirredatroormtemperature for fourv hours; then allowed to stand iforitwentyfour hours. The slurry was filteredas dry rsipossible with suction,washed with ether and. dried. irrithervacuum oven at-roomftemperature.The finely dividedsolid was: added to.2 litersof ice water and rapidlyTheslurry was filtered with suction. slurrie'din' ether, filteredagainfandthe white 'crys The analytical sample(fronrethanol)"me1ted*at"105?5 Analysis.--Calc. for C H BI N O C, 50.2;H, 7.9; N, 5.3; Br, 30.4. FoundtiC, 5110; 3e.2.-

7,18-diaza-6,19-dioxotetracosane-1524-bis(pyridinium perchlorate) To-a--2 1. flask equippedi withacondenser; was added 285 g. (0.54 mole) of7,18-diaza 6,19 dioxotetracosane- 1,24-dibromide and 1500 ml. ofdrypyridine. The solution was heated to reflux for'one-and one-half hours,

although the quaternary saltprecipitatedout as an'orange oil after thefirst fifteen minutes: The mixture. was. chilled, the excesspyridinedecanteiqand.=thegoldensyrup slurried several times with ether,the ether being decanted. The oil was' final1y dissolved in a minimumotmethanol, and ether added until no more oil precipitatedfromE-thvsohltion; The pi oduct was chilled, the ether decanted, and theremaining traces of solvent removed on the steam bath under vacuumleaving a viscous orange oil.,with no pyridine odor.

The oil was dissolvedjin 500 ml. of methanohand withl eflicient sti'" ga solution of182-g. (1.30 mole;

%" excess) of" sodium. perchlorate monohydrateiin: 1600 ml. of acetonewas added. The precipitating sodium.

bromide formed a thick slurry. The mixture was .con-i centrated onthe=steam .bath toone-halfth'e original volume and the slurryfilteredwith suction. The 'solu-' tion was now concentrated to about 400' ml.andthis sticky residue heated'andslurried with one l. of acetone.

Thesodium bromide which had precipitated was filteredi Twoh'undred'" m1.of methanol was added, andthe solutionchilledin a" oflandthe solutionconcentrated to V2 1.

Dry. Ice acetone bath. Ether-was slowly added; with vigorous scratchinguntil" the cloud "point' was reached;

or until a solid began precipitating from solution; If

an oil formed first, vigorousscratching of the oil usually resulted inthe ,oil solidifying; or ether could be removed, the solution chilledagain, and the process repeated. The sticky cream: colored solid.meltingat' 63f wasadissolvedin aof '-'methanol, .chilled in. a Dry Ice-)-acetone: bath and "ether? slowly added 'withLscratching; until a' solidbeganprecipitatingfrom solution; The

white semi-crystalline solid melted :at. 64-66.5. Another:recrystallization of the 'solid from methanol-ether fimther same mannerraised'th'e 'meltingpoint'to 67.'.Q The cream-colored solid weighed 338g. (86.5%

The analytical sample when recrystallized several-tinies frommethanol-ether melted 'at'72.-.75.

Analysis.Calc. for c." H .c1 N-0 0,153.1;11-1; 7.2;-

N, 7.8; C1, 9.8. Found:.C, 529; H, 7.4; N, 7.9; Cl, 9.5.

a I COMPOUND XI 7 p 1 0,15-diaza-9,'16-dibxotetracosane-1,24 dibr0mideAsolution of 30.8 g. (0.19 mole) of 1,4-diaminobutane dihydrochloride in250 ml. ofwater was added to a1 1. flaskequipped withstirrer anddroppingfunnel. A solu-' tionof 38.4 g.-.(0.96 mole.) of sodiumhydroxide in 200 mlQof-water-was added and the mixture chilled below10"; The w-bromopelargonyl chloride (l03 g., 0.38 mole) was..addedthrough the droppingfunnel .at such a rate that. thetemperature of theslurry never rose above 10. After stirring at 010 for two hours, thewhite solid.

was filtered as dry as possible, then washed withethen The crudewhitesolid,'recrystallizedfrom methanolrether,

gave .6715... (67.5 percentlof dibromide .meltingat 11654119".

10,=15 didza-9,16 dioxotetrac0saner1 ,24-bis (pyridinium perchlorate)"-A-" solution -of 6725' 5. (01 129 moldy ot-z 1035M 99,16-dioxotetracosane-l,24-dibromide in 275 ml. of dry pyridine wasrefluxed for two hours. An oil precipitated from solution after thefirst half hour. The pyridine was removed completely from the product onthe steam bath under vacuum. The residue was dissolved in 300 ml. ofmethanol and added to a solution of 43.0 g. (0.31 mole) of sodiumperchlorate monohydrate in 300 ml. of methanol with vigorous stirring.After heating for one hour while concentrating the solution to one-halftheoriginal volume, the precipitated sodium bromide was filtered off.This procedure was repeated until sodium bromide no longer precipitated.

The solution was chilled in Dry Ice-acetone and ether slowly added withintense scratching. The solvent was decanted from the sticky solid thatseparated. This semisolid was dissolved in methanol, chilled in a DryIce-acetone bath, and the treatment with ether repeated. A solid meltingat 6575 (cloudy) was obtained. Recrystallization of this solid frommethanol-ether in the same manner gave 71 g. (72.5 percent) of productmelting at 7678 with preliminary softening at 72.

An analytical sample was obtained from methanol upon chilling in a DryIce-acetone bath, melting point 80- 825.

Analysis-Cale. for C H N O Cl C, 53.1; H, 7.2; N, 7.8; Cl, 9.8. Found:C, 53.6; H, 7.5; N, 7.8; CI, 9.2.

COMPOUND XVH Ethyl N-w-bromocaproylglycinate A mixture of 19.5 g. (0.10mole) of w-bromocaproic acid and 12.9 g. (0.10 mole) of carbethoxymethylisocyanate (mildly exothermic) was heated on the steam bath underanhydrous conditions for six hours. An evolution of carbon dioxide wasevident during the reaction. A yellow oil resulted which was dissolvedin 50 ml. of dry ether, cooled, and petroleum ether added slowly. Awhite crystalline solid weighing 18.4 g. (65.7 percent) and melting at46.548.5 was filtered from the mixture.

The analytical sample of the ester was obtained as matted white needlesfrom ether-petroleum ether, melting point 46.5-48.5

Analysis.Calc. for C H O NBr: C, 42.9; H, 6.4; N, 5.0; Br, 28.6. Found:C, 42.9; H, 6.3; N, 5.2; Br, 28.7.

N-w-bromocaproylglycz'ne N-w-bromocaproylglycine ethyl ester wasprepared as above from 52 g. (0.27 mole) of w-bromocaproylglycine and34.4 g. carbethoxymethyl isocyanate (0.27 mole) and used without furtherpurification for the hydrolysis.

The pale yellow ester was dissolved in 100 ml. methanol and hydrolyzedby slowly adding a solution of 21.2 g. (0.53 mole) sodium hydroxide in22 ml. of water. The temperature was not allowed to rise above 50 duringthe addition. After one-half hour, the solution was poured into a largevolume of ether, precipitating the sodium salt. The White solid weighed86 g. (contained some NaOH) and melted cloudy at 174177.

Forty grams of the above salt was dissolved in 20 ml. of water andneutralized to a pH of 3 with 1:1 hydrochloric acid. The mixture wassaturated with sodium chloride and then extracted several times withwarm benzene and ethyl acetate. The extracts were dried over sodiumsulfate, and the solvent removed, leaving 21.0 g. (57 percent) of thesubstituted glycine as an oil. The acid is extremely ditficult toextract, being only slightly soluble in benzene and ethyl acetate,almost completely insoluble in ether, and fairly soluble in water, evenwhen the aqueous solution has been saturated with sodium chloride.

An analytical sample of the acid was obtained from methanol-petroleumether and melted at 69.5-70.5

Analysis.Calc. for C H NO Br: C, 38.1; H, 5.6; N, 5.6; Br, 31.8. Found:C, 38.9; H, 5.4; N, 4.7; Br, 30.8. 2

10 7,10,17,20 tetraza 6,9,18,21 tetraox0hexac0sane-I,26

dibromide Seven grams (0.042 mole) of hexamethylene diisocya nate in 50ml. of dry benzene was added to 21 g. (0.083 mole) ofN-w-bromocaproylglycine in ml. dry benzene. The solution was refluxedvigorously. After ten hours, the cream-colored solid that graduallyseparated in the reaction mixture was collected on a filter and dried;yield, 16.3 g., melting point 160.

The powder was dissolved in 250 ml. of methanol, filtered, andcrystallized; melting point -175 softening at 150. A recrystallizationfrom ethanol gave 10.3 g. (41 percent) of white powder of melting point-178 (softens at 160).

Analysis.--Calc. for C H N O Br C, 45.2; H, 6.8; N, 9.6; Br, 27.4.Found: C, 47.6; H, 7.0; N, 10.3; Br, 20.4.

7,10,17,20 tetraza 6,9,18,21 tetraoxohexacosa ne-L26- bis(pyridiniumperchlorate) Four grams (0.0069 mole) of the dibromide just above wasrefluxed vigorously with 25 ml. of pyridine and 25 ml. of ethanol forthree hours. The ethanol and pyridine were removed completely on thesteam bath under vacuum, leaving a yellow water-soluble gum.

The gum was dissolved in 25 ml. of methanol and a solution of 2.1 g.(0.015 mole) of sodium perchlorate monohydrate in 50 ml. of acetoneadded. The solution was heated until only 20 ml. of a slurry remainedand the precipitated sodium bromide filtered off.

The product was precipitated from ethanol-ether as a sticky white solidwhen chilled in a Dry Ice-acetone bath. This sticky solid wasrecrystallized from methanolacetone as a Wax which when triturated withether turned to 2.0 g. of a white solid of melting point 90100 dec. (38percent).

Analysis.--Calc. fOl' C3 H5 N5O12Cl2: C, H, N, 10.8; C1, 9.1. Found: C,47.7; H, 6.4; N, 10.7; C1, 8.1. v

The alternate procedure of preparing quaternary salts of bis-amides fromthe 0:,w-dih3lld6 (XRCONI-KA) NHCOR'X 7,18 diaza 6,19 dioxotetracosane1,24 bis(dimethylamine hydrobromide) A mixture of 21.0 g. (0.04 mole) of7,18-diaza-6,19- dioxotetracosane-1,24-dibromide (prepared as above), 75ml. of dimethylamine, and 25 0 ml. of ethanol was heated in a .Paar bombfor 16 hours on the steam bath, then allowed to cool slowly to roomtemperature. The 5 g. of crystalline solid which precipitated wasfiltered off and identified as starting dibromide.

The orange filtrate was concentrated to about 50 ml. and ether slowlyadded while chilling in a Dry-Ice-acetone bath. A water-soluble tansolid (15.3 g., 62 percent yield), M.P. l18.5l23.5 was obtained.

A solution of 11.4 g. (0.0185 mole) of 7,18-diaza- 6,19dioxotetracosane-l,24-bis(dimethylamine hydrobromide), in 50 ml. ofwater was added to a solution of 7.7 g. (0.056 mole) of potassiumcarbonate in 50 ml. of water. Chunks of ice were added until no moreamine precipitated and the solid was filtered oil, M.P. 108110, wt. 7.0g. (83.5 percent). The amine was dissolved in acetone, filtered, and thesolution chilled in a Dry-Iceacetone bath while slowly adding other. Awhite crystal- 7 line solid (4 g. 48 percent), M.P. 110111.5 wasobtained.

Analysis.Calc. for C H N O C, 68.8; H, 11.9; N, 12.3. Found: C, 68.0; H,11.5; N, 12.2.

Twenty ml. of ethanol, 2.1 g. (0.011 mole) of methylp-toluenesulfonateand 2.3 g. (0.005 mole) of the above Weighing ;4;0 g;(98:percentryield) 182-184 C.;

. After. twozrecrystzilliiations from methanoh'ether;

white a crystalline hygroscopic solid was .obtained; 3:8 ge;..M.Rr.188t-190;x. 1 The. analysisrindicates that the salt maylco'ntain;water ofi crystallization; or

solvehtrroficrystalliiatibni 6. 8582] Found z 56Z6;H,:.8Z8; N; 7.5; .S,8.6;

The-preparation of ta monoamide 1 as indicated in; the flow diagramabove is carried out as follows:

3-izzo-4-oxotetradecane-1,14-dibromide Fifteengrams :(0.073 mole) :of 2hromoethylamine --hydrobromide and- 8.4- g.. (0.21 mole) of sodiumhydroxide weredissolved in 75. ml. of'ice water. Keeping the temperatureatim j 2058* g." (I073f-mole) Offw-bI'OIIlOUIIdficanoyl chloride gwasslowly i addedthrough azdropping' funnel? After the completefadditionofthe chloride; the shin-y was stirred at--' room temperature for 1 /2hours; then filtered with suctiomi. V V IAnianalvticallypure'product'r(16 g, 59 percent) was obtained byrecrystallization from 7 alcohol, M-l.

3j-'aza.-4- oxotetradecane91.1.4-bis(pyridinium perchlorate) TTwentyfiveml';ofifiryspyridinerandfifizg; (0;0 1-3;mole) 053azaat-oxotetradecanee1,14 dibromide were: heated. at reflux for three hours.The excesspyridine wasremoved and tli 'oilE slurried JseveraL-timeswith: ether to. remove traces ofipyridine; I

'The residual oil was dissolved in 25 ml. of methanol,andaiafisolution:=ofar4;6 :g; eta-sodium; perchlorate: monohydrate in 25ml. of acetone: was added-;.' The solution was concentrated-'on-thesteam bath-to. one-half the volume and the inorganic salt"fi1tered'ofi."This procedure was carr-ie'd -out until no more sodiunr bromideprecipitated upon concentrating the oil. The water-soluble oill wouldnot crystallize afterseveralfattempts; therefore, it .was:isolated=as apale .ye1lo. w oi1..(4 .g.) r r The other bis quaternary. compounds of'the invention may be prepared in a similar manner by selection of theappropriate diamine 1 for reaction: with the I appropriate organic acidor organic acid halide.-'

The-following' examples illustrate the use of thebisquaternary salts' ofthe invention in photographic emulsions? V EXAMPLE-.1,

A high-speed bromoiodide emulsion wasprepared, chemically sensitizedwithsulfur and gold; compounds and-optically sensitized with'a cyanine dye.The amounts of the bisquaternary nitrogen compounds-shown in Table 1below were added to samples of-theemulsion alone and *together with anazainde'ne stabilizing agent; The emulsionv samples were thencoated;exposed'on. a sensito'meteriand developed-for' S -minutes at 68 F..inithe developer givenabelow: The speed, gamma and'fogvalues obtainedby sensitometric evaluation of the-:developed samples" are also.sh'ownririthe table. The speed .values showntare'expressedat100"(14-.1og'E') where. E is the exposure in mete'ricandle" secondsrequired". to produce in tt-he'iemulsion a -density .of: 0z3 above: fog;

'LT B' i Nlimmrear-m speedro 932..."; Gondola-"-1101; 318 1. -0;-169304-1-.- LII-DiaZa-E Z-GioXOtetradecaue-l, 4 328; 1. .18-

V bi's(pyridinium perchlorate) (I) 0.75 V g.'/mol/AgX.- 1

3,14-.Diaza'-2 ,--dioxohexadecane-L16 I 328 v 1.

' EXAMPLE 2 L An; emulsion was. provided as in Example 1 andtheadditions shown in Table -II Were-made to" samples of the emulsiomSensitometric evaluationmade-as :deScribed -in Example 1 gavetheresultsshown-in the tablet TABLE:- I1

Number. Feature Speed. Eng

Control; 310 i.11 0. 15 7,14;l)laz a-6,1h-dioxoeicosane-LZO-bis- 334 1.20 .22 (plyritllmium j'perhlorate)-(v)075. .i .g,mo-... 7,18 Diaza-6;19di0X0tetfaG0SaJJedfl4 331 1:07

bls(pyridin ium perchlorate) (Y1) 0.75 g./mol.' V 1164-Hydroxy-6-methyl-1,3,3a,7-tetra 316 1.11 15 zaindene (XXX) 3.0g./mol-.123-. (XXX) 3 0 g ImOH-( 0 75 g lmol 337 1. 20 .18 124.. (XXX) 3.0g./m0l+(V) 2.25 g./1110l 343 1. 17 V 19 125.. I (XXX)-3.0g./mol+(VI)0.75 g./-mol 337 1. 07 21 126 (XX-X-)-3.0'g. /m01+(VI)2.25'g./m01 346 1.07- .21

7 EXAMPLE 3. An emulsion was provided 'as in 'EXam'plel'l but with:theaddition to 'samples'of the emulsion of'com-pound'sIX and XI, assh'ownin Tabl'e'III. Processing was'carr'ied out as in"Exa1'n'ple .11for evaluatir'igthe' emulsion sejnsi? tivity and other characteristicsof the emulsion.

TABLE IV Number" Feature Speed 'y Fog- 1977 Control; 308' 1. 0.17 19827,14- D.iaza -6;15rdioxoeicosane 1,20-bis 327" 1; 06 .24

r (5-ethyl-2-rnethyl-pyridinium per- 7 chlorate) XVI) 0.75 gJmol.198341..-. 4,11;Diaza-3;12-dioxotetradecane-l,141 325' 1. 32 21 g gbis(5 ethyl 2 methyL- pyridinium V perchlorate) (II) 0.75 gJIuol.1985;... 7,10,17,20Tetraza-6,9,18,21-tetraoxo-1, 322 .1. 26' 2026-bis(pyr1dinium perchlorate) (X-VII)0.75g./mol-. V 2005 4 Hydrow 6methyl 1,3,3a,7 tetra- 317 1. 35- 14 zamdene (XXX) 3.0 g./mol. (XXX)8.0'gw/mol-l-(VI) 0.75 gJmoll; 325; 1; 19 3 .19 -(X XX) 3;0 gJmol-i-(VI)2.25 gJmol... 329 1. 23 21 (XXX) 3; g /m0l+(II)'0.75 g./n.olL. 326 1. 27.17- (XXX) 3.0 g./mol+(l1) 2.25 g./ni 325 1.21 .19 (XXX) 3.0 g. /mol+(X'VII) 0.75 g./n1ol 328 1. 35 17 (XXX) 3.0 gJmoH-(XVII) 2L25 gJmoll329 1. 30' g 18' EXAMPLE 5 A fast bromoiodide emulsion was chemicallysensitized with sulfur and gold compounds and optically sensitized witha combination of cyanine dyes. In addition, 3.0 grams per mole of silverhalide of 4-hydroxy-6-methyl- 1,3,3a,7-tetrazaindene and 0.75 gram permole of silver halide of a polyethylene oxide of average molecularweight 1500 were added. The amounts of the alkylene bis-pyridinium saltand compounds X and XI shown in 14 fixation, silver bleaching and finalfixation. Color Process 1 was carried out at 75 F. as follows: (1)Negative development-l minutes (2) Reversal flash exposure (3) Colordevelopment-15 minutes (4) Silver bleaching-8 minutes Fixing-3 minutesThe negative developer had the following composition:

10 c 0 1i rs... 1.0 Table V were then added and the emulsions coated.Test- 90 F (32 C te in was carried out as EX 1 1 th fr m SOdll-llllhexametaphosphate grams 2.0 g m amp 6 upon es N-methyl p-aminophenolsulfate ..do.. 6.0 coated emulsion samples and other samples of eachemul- Sodium sulfite desiccated do 50 0 o men were incubated for 1 weekat 120 F. and 50 per- Hydmquinone 64) cent relative humidity. Stillother samples of each Sodium carbonate, monohydrated 3 5 0 emulsion werestored under room conditions 78 F. potassium bromide 29 K p ug and evelped with the same developing solusodium thigcyanate 5 1111 S 0 111 ample1 with the result shown In Table 0.5% solution (6-nitrobenzimidazolenitrate) -cc 12.0 V. Consideration of the Fog data in the table shows0.1% solution of potassium iodide cc 10.0

TABLE V Fresh Tests llniubfztggr 3 Moths,ig8 F.,

, w e Number Feature ep g P- '7 F g Sp. 7 Fog Sp. 7 Fog 7s Control 31.12 0.15 343 1. 01 0.16 337 1. 05 0.16 7820Hexladelcamgthylene-l,16-b1s(pyrld1niu1n perchlorate) 0.15 356 1.10 .24359 1.10 .22 353 1. .20

g. mo g 7821 liexladefaingtihyleue-l,16-bis(pyrldinium perchlorate) 0.3356 1.24 .30 359 1.02 .34 359 1.23 .26

g. mo g 7822 Hexladefaingghylene-l,16-bls(pyridlnium perchlorate) 0.6355 1.17 .29 345 .90 .48 356 1.23 .31

g. m0 g 7826 7,IB-Dlaza-G,19-dioxotetracosane-1,24bis-(pyridinlum per-352 1.09 .19 364 1.01 .19 351 1.27 .19

chlorate) (X) 0.45 g./mol AgX. 78277,18-Dlaza-6,19'dioxotet'racosa11e-1,24-b1s-(pyndm1um per- 358 1.14 .20362 1.20 .20 353 1.32 .19

chlorate) (X) 0.75 g./mol AgX. 78287,18-Diaza-6,19-dioxotetracosane-1,24-b1s-(pyrldlnlum per- 357 1.33 .23362 1.18 .22 354 1.25 .20

chlorate) (X) 1.2 g./mol AgX. v 783910,15-Diaza-9,l6-dioxotetracosane-1,24-b1s-(pyridnnum per- 352 1.22 .18352 -1. .20 350 1.18 .17

chlorate) (XI) 0.45 g./mol AgX. 784010,15-Diaza-9,l6-dioxotetracosane-1,24-b1s-(pyridmium per- 357 1.25 .19359 1.15 .19 354 1. 33 .17

chlorate) (XI) 0.75 g./mo1 AgX. 784110,15-Diaza-9,lfi-dioxotetracosane-l,24-bis-(pyridimumper- 358 1.38 .19361 1. 20 .20 356 1.28 .17

chlorate) (XI) 1.2 g./mol AgX.

that the emulsions containing compounds X and XI of the invention weremore stable thanthe emulsions containing the alkylene bis-pyridiniumcompound of the prior art.

EXAMPLE 6 The use of the bis-quaternary salts of the invention in colorphotography is illustrated in this example.

A sulfur and gold sensitized gelatino silver bromoiodide emulsion wasripened to maximum sensitivity. To this emulsion was added an opticalsensitizing dye that extended the light sensitivity to 6000-7000 A. anda hydrophobic cyan color former suitably dispersed in a high boilingorganic solvent. A portion of this liquid emulsion received no furthertreatment; to another portion was added one of the compounds describedbelow. Both portions were coated on film support, and the dry films wereexposed to red light in an intensity scale sensitometer. The exposedfilms were processed in reversal Color Process 1 and in the 5248Negative Color Process 2 with the results shown in the following table.Color Process 2 was carried out as described by Hanson and KisnerJSMPTE, 61, 667-701 (1953) for Color Negative Film, type 5248 involvingthe steps of color development,

The color developing solution above had the following composition:

The silver bleaching solution above had the following. composition:

Water F. (32 C.) liters 1.0 Potassium dichromate grams 5.0 Potassiumferricyanide do 70.0

Potassium bromide do Determined by measuring the shift of the reversaldye curve on the log E axis at a given density below maximum density.

1 Determined by measuring the shift of the negative dye curve on the logE axis at a given density above minimum density.

EXAMPLE 7 A high-speed bromoiodide emulsion chemically sensitized withsulfur and gold compounds and optically sensitized with acyanine'fidyewas-providedr Tcr'various' mg, (3) the second digestion orafter-ripening;-to olgvtairi increased, sensitivity (Mees, ,The Theoryof, the Photo: graphic Process,-1942,,page'3). The sensitizing agentsmay be added 'ataiiy 'stage,,preferably after the final. digestion.

The photographic'emulsions whiclijwe'use are'fof 'thedeveloping-out'type' and bestresults have been obtainedv withgelatino-silve'r bromoiodide emulsions. ewever,

emulsions of varying silver halidecontent maybe usedi,

The emulsions arechemically sensitizedbyany of the accepted proceduresin addition to sensitizing with the bis-quaternary salts of theinvention. The emulsions may be digested with naturally active gelatin,or sulfur compounds may be added such as those described in SheppardU.S. Patents 1,574,944 and 1,623,499, andSheppard and samples of theemulsionwere added thegingredients shown-= in the following table-'Sensitometiic 'evaluation of the samples was carriedoiifas imEiia'mple 1with the result shown in the table:

TABLE-V||- Number Feature Speed jy Fog 1212 Control 304 1.14 .08 12144,11-Diaza-3,12-dioxotetradecane-L1 1-' 1 313' 1.42 .10

' 1s(pyridiuium perchlorate) (I) .75

g./mole AgX. ,7 V 1216 2,13-Diaza-3,12- ioxotetradeeane-LM- 310 1.26 10bis-(pyridinium' chloride) (Ir) .75- gJmole AgX. V 12174-Hydroxy-G-methyl -1,8,3a,7-tetra j 309 1.2% .08

zaindene (XXX) 3.0 g./mol AgX." 7 (XXX) 8.0 g ./mol+ (I) .75 g./mol AgX,314; 1123. 10 (XXX) 3.0 g./mol+(I) 3,0 g./mol Ag-X- 321 1. 17 10 s x?3.0 g./ oi :.75=-g.lmol:; 311' 1.22 .10 g r (XXX) 3.0 gJmQH-(Ir) 3.0g.lmol 312 1.19 .11

AgX.

color film containing couplersinthe emulsion-layers'was developedfther'cin," speed increases were 'obtainedparticularly for thegreenand'i'ed-sensitive emulsiontiayers.

As indicated in the above examples,itmay be desirable to incorporate astabilizing agent into the emulsion sensitized'with'the bis-quaternarysalts of-the invention .towredu'ce fogitoj'normaljlevels'l 'Azaindenesparticularlysuib able forthis purpose are those described the patrol etal'; U.S. 'patent application Serial'No s. 627,135 and 627;186;,file'cl- Dec. 10, 195 6,1- foneiample-fthe' following: 5-

carboxy 4 hydroxy-l,3,3a,7-tetrazaindene 1,2 bis(4= Brigham;U.S. Patent2,410,689

The emulsions may also be treated with salts of the noble mans such asruthenium, rhodium, palladium, iridium and platinum, all of which belongto group VIII of the periodic table of'elements and have anatomic weightgreater than 100. Representative compounds are ammonium chloropalladate,potassium chloroplatinate and sodium chloropalladite, which are usedfor'sensitizing:

in amounts below that which 'produc'esany substantial rag inhibition, asdescribed in Smith and Trivelli II-.8; Patent-i 2,448,060, and asanti-,foggants in highe'r amounts, as de:. scribed in'Trivelli and SmithU.S'; Patents 2,566,245'aiid The emulsions may also be-chemically'sensitized with. gold salts asrdescribed inwalle'r" and-D'odd-KJLS.Patent.

2,399,083 j or stabilized with gold; -salts;"-as}-de'scribed iu'Damschroder US. Patent 2,597,856and Yutzy'and Leer makers US; Patent2,597,915. Suitablefcom'pounds potassium chloroaurite; potassium-aurithiocyanate, p9 tas'sium chloroaurat'e'," aurictrichloridandx2aur6si1lfo benzothiazolemethochloride. J The emulsions may also bechemically sensitized with reducing agents such as stannous salts(Carroll U.S. Patent 2,487,850), polyamines such as diethylene triamine(Lowe and Jones U.S. Patent 2,518,698), polyamines such as spetmine(Lowe and Allen U.S. Patent 2,521,925), or bis-(*fl-anrinoethyl) sulfideand'rits waten solubleisalts (Lowe andJones; U.S;1Patent-2,521,926); v.Other compounds useful:for-,suppressingJthe-iogdcivl: of the emulsionsensitized with the bis-quaternary;:con'1-;-'v pounds of the inventioninclude the mercury compounds of Allen et a1. U.S. Patent 2,728,663,Carroll and Murray U.S., Patent 2,728 ,664. and *Leubner and .Murray Uissf'P-atent 2,728,665 granted Decernber'27, 1955; 'andthetorganic':mercury compoundsofiCarroll ethltUSl-Patent 2,784,090granted'March%5;.1957: T a

- The emulsionsmay.: also-. contain polyalkylenaioxide's andiderivatives.there'o'fl-sucli as the-polyethyleneiglycolsg=- in addition: to the:bis=qu aternary;compounds10f the inven' tion';Suitable:polyalkylenevoxides andpolyalkylene oxide derivativesarezde'scribedsin-Blake :US: fPatent r2;441;389;1 May 11,-l94.8',--:Blake etalt UzS;v Patents 2,400 532; May: 21, 1946, 2,423,549,July. 85, 11947, and lennings iet-ale'UsSzi Patent-2,577,127, December4;'19-5'1.i

- Other stabilizing v agents may bezaddedtdttliezemnlsions containingthe bis-quaternary 'sal't's isuellu-astheenietal'rin organic saltsof-U.S.i patent; application Serial-'No. :493','043', filed :March=8,1955,5by 'JJEJJones;

V The chemical-z sensitizing agents tangl other addenda 21 which we havedescribed may; be used in valfiqnskindsoi photographic emulsions, e.g.,various silver salts may be 17 used as the sensitive salt such as silverbromide, silver iodide, silver chloride or mixed silver halides such assilver chlorobromide or silver bromoiodide.

The dispersing agent for the silver halide may be gelatin or otherhydrophilic material such as collodion, albumin, cellulose derivativesor synthetic resins.

Since the coupler-containing emulsions sensitized as described with thebis-quaternary salts are adapted particularly for use in colorphotography, they Will ordinarily comprise the emulsion layers ofmultilayer color films which emulsion layers are customarilydifierentially sensitized to the primary regions of the visible spectrumand contain coupler compounds producing dye images of colorscomplementary to the sensitivity of the emulsion layers. In arepresentative color film, one or more of the differentially sensitizedemulsion layers may be sensitized with the bis-quaternary salts, and ina typical example emulsions sensitized to the red, green and blueregions of the spectrum are superimposed on the support in that orderand contain cyan, magenta and yellow color-forming coupler compoundsrespectively. A yellow filter layer is advantageously interposed betweenthe blue and greensensitive emulsion layers.

Since the emulsion layers sensitized with the bis-quaternary salts ofthe invention may contain coupler compounds they can be readilyprocessed by well known methods to yield color negatives directly orpositive images by means of well known reversal processes. That is,after initial exposure of the emulsion to a subject a developer of thep-phenylene diamine type will produce a colored image negative inrespect to the subject. Likewise, if development of the emulsion layeris first carried outwith a non-color-forming developer followed byreversal exposure of the residual silver halide and then colordevelopment, a colored positive is obtained as described in the examplesabove.

The coupler compounds used in the emulsion layers sensitized with thebis-quaternary salts, are any of the well known compounds which combinewith the oxidation product of primary aromatic amino (p-phenylenediarnines) silver halide color developing agents to form dyes, forexample, the phenolic couplers of U.S. Patents 2,266,- 452, 2,362,598,2,589,004, 2,474,293, 2,521,908, 2,423,730 and Fierke U.S. patentapplication 476,561; the pyrazolone couplers of U.S. Patents 1,969,479,2,369,489, 2,600,- 788, 2,618,641, 2,511,231 and the open chainvreactive methylene couplers of U.S. Patents 2,298,443, 2,652,329,2,407,210, 2,271,238 and McCrossen et al. U.S. patent application SerialNo. 575,099, filed March 30, 1956. Likewise, the emulsions may containcolored color-forming couplers as described in U.S. Patents 2,521,908,2,706,- 684, 2,455,169, 2,694,703, 2,455,170 and 2,453,661.

The couplers may be dispersed in the emulsion layers by means of an oilycoupler solvent according to the methods of U.S. Patents 2,304,940 and2,322,027; However, if as may be the case, the couplers containsolubilizing groups such as SO H groups which render the couplerssoluble in alkaline solution, the oily coupler solvent may be dispensedwith and the couplers can be added to the emulsion from aqueoussolutions as their alkali metal salts.

What we claim is:

1. A photographic silver halide emulsion containing a quaternaryammonium salt having a general formula of the class consisting of QRCONH(A) NHCR'Q' and QRCONHAQ' wherein Q and Q each represent radicals of theclass consisting of wherein R, R3 and Re represent lower alkyl groups, Zrepresents the atoms necessary to complete a hetero, cyclic nucleus ofthe class consisting of pyridinium and q m, R and R e ch epre n alky engrou s linked directly to the quaternary nitrogen atoms, of fsaidradicals, n represents a positive integer of from 1 to 2, A represents amember of the class consisting of and r n n. and 11." p e n positiveintegers or. from about 1 to 10 there being from about 14 to, about '30at ms p e nt in he h rtes l nea hain of atom i k said quaternarynitrogen atoms.

2. A photographic silver halide. emulsion containing a qu ternary sa avig h en formula QRCONHANHCORQ': V wherein Q and Q each represent radicalsof, the glass consisting of and wherein n and n" represent positiveintegers of from about 1 to 10, there being from 14 to about 30 atomspresent in the shortest linear chain of atoms linking said quaternarynitrogen atoms.

I9 7 3. A photographic silver halide emulsion containing} quaternaryammonium salt having the general formula if? QRCONHANHCOR'Q' e wherein Qand Q each represent radicals of theclass consisting of wherein R3, Rand R4 represent lower alkylgroups, Z represents the atoms necessary tocomplete aheterocyclic nucleus of the class consisting' of pyridininmand quinolinium, R and R each represent. alkylcne groups linked directlyto the quaternary nitrogen atoms "of said radicals, A represents analkylene group of from about 1 to carbon atoms, there being from about14 to about 30 atoms present in the shortest-linear'chain of atomslinking said quaternaryfnitrogen atoms.

4. A photographic silver halide emulsion containing the compound 7,14-diaza 6,1'5-dioxoeicosane 1,20 bis(pyriperchloratefi 5. Aphotographic silver halide emulsion containing the compound7,18-diaza-6,19-dioxotetracosane 1,24 bis (pyridinium perchlorate).

6. A photographic silver halide emulsion containing the compound10,15-diaza-9,16-dioxotetracosane-1,24-bis (pyridinium perchlorate).,

, 7,, A photographic silver halide. emulsion containing the compound12,15-diaza-11,16'- dioxohexacosane- 1,26- bis(pyridini1im perchlorate).8. A photographic silverhalide emulsion containing the compound,12,19-diaza- 11,20 dioxotriacontane-1',30 bis(pyridinium perchlorate). lJ 1 9. The emulsion of claim 1 furthefcontaining a coupler compoundreactive with the'oxidation products of a p-phenylcne diamine silverhalide devcloping agent to forma'diei' i 10. The emulsion of claim 2further containing a coupler compound reactive with the oxidationproducts of a p-phenylene diamine silver halide developing agent to forma dye.

11. The emulsion of claim} further containing a coupler compoundreactive with the oxidation products of ap-phenylene diamine silverhalide developing agent to form'adye.

'12. The emulsion of claim 1 further containing ,an azaindenestabilizing agent. l V 13. The emulsion of claim Z'further containinganazaindene stabilizing agent. i w

14. The emulsion of claim 2 further containing an azaindene stabilizingagent.-

15. Theemulsion of claim [wherein the silver halide is sulfurand goldsensitized-.- V

16; A method for increasing the speed of'a silver halide '5'20 emulsionwhich comprises developing said emulsionin the presence of a quaternaryammonium salt having a general formula of the class consisting of VQRCQNH(A) NHCOR'Q' wherein Q and Q each represent radicals of the classconsisting of wherein R R and R represent lower alkyl groups, Zrepresents the atoms necessary to complete a heterocycliclnucleusof theclass consisting of pyridinium and quinolinium,-R and R each representalkylene groups linked directly to the quaternary nitrogen atoms of saidradicals,'n represents a positive integer of from 1 to 2, A represents amember of the class consisting of 2)n' 2)n' n" V z)n- N a)a" 2)n"- I-(a)n' z)n" -'(CH,) 'COO(CH V z)nz)n'" cH ),,.NHcoNH(cH, -(CH 'OCONH(CH,)

and

wherein n and 11: represent ,positive integers of from about 1 to 10,there being firom about 14 to about 30 atoms present in the shortestlinear chain of atoms linking said quaternary nitrogen atoms.

References Cited in the file of this patent UNITED STATES PATENTS2,288,226 7 Carroll et a1. June 30, 1942 2,419,975 Trivelli et al May16, 1947 2,784,090 Carroll Mar. 5, 1957 a f FOREIGN PATENTS 115,971

Australia Oct. 15, 1942 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No 2 9 iO 85l June 14 1960 Dorothy Ja Beavers et al0It is hereby certified that error appears in the-printed specificationof the above numbered patent requiring correction and that the saidLetters Patent should read as corrected below.

Column 1 line 27 for "emulsions read emulsionse column 18 line 18 forthat portion of the formula readin -=-(CH read -=(CH n column l9 line 51for the claim reference numeral "2" read 3 column 2O line 30 for thatportion of the formula reading =-(CH read Signed and sealed this llthday of April 1961a (SEAL) Attest:

ERNEST W. SWIDER ARTHUR W. CRQCKER attesting @flicer Acting Commissionerof Patents

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING A QUATERNARYAMMONIUM SALT HAVING A GENERAL FORMULA OF THE CLASS CONSISTING OF